Semiconductor devices such as bipolar transistors and field effect transistors are widely used in electronic circuits. Use of these semiconductor devices requires that they be properly biased. When biased correctly, these devices operate in predictable ways and are invaluable as elements of electronic circuits.
An electronic circuit with voltage levels that vary beyond the voltage capabilities of semiconductor devices can cause problems with the biasing of these same semiconductor devices. Semiconductor devices often are biased by constant voltage references. This constant biasing prevents undesired biasing of semiconductor devices which can cause the failure of an electronic circuit to perform as desired and even the destruction of some devices. However, in many instances, semiconductor devices are biased in electronic circuits with voltage levels that change with time along with other voltage levels in the electronic circuit. Those changing bias voltage levels can create problems with the proper biasing of the semiconductor device, especially where other bias points of the device are constant voltage levels.